This is a neat example of that old canard about feminists/liberals/whoever not having a sense of humor:
Fox News political and foreign affairs analyst Monica Crowley reacted to a report that Georgetown Law student Sandra Fluke got engaged to her boyfriend by tweeting: "To a man?"
Following criticism of her on Twitter, Crowley wrote: "I love exposing the Left's total lack of a sense of humor."
As Media Matters has documented, Fluke has come under vicious attack by conservatives following her testimony before the House Democratic Steering and Policy Committee. Most infamously, Rush Limbaugh called Fluke a "slut" and a "prostitute."
Or put it in different terms: If you don't have the same basic beliefs, the ones which make you go bwahahah! then you don't have a sense of humor.
In this case there is no joke without certain basic beliefs. Indeed, Crowley's statement makes no real sense for someone who doesn't know the backstory about Sandra Fluke: That she gave testimony about the question whether Catholic universities cause hardship if the insurance policies they offer do not cover the contraceptive pill.
But even knowing that doesn't explain the joke to someone without certain basic beliefs, unless one assumes that the joke is a surrealist one.
No. To get the joke you need to know something about what the basic beliefs of Monica Crowley might be about feminists or women who speak up on these types of questions. If you know those then you get why she thinks her statement is funny.
All this is quite trivial. But knowing what it means when someone accuses you of not having a sense of humor (assuming that you do have one) can be helpful. It's mostly about a demand that the underlying basic beliefs should be shared.
It's the most effective responses that are trickier. I've had some success by using reversals and then demanding that people get the humor in those, too.